Initial Commit

ViewportRestrictions/PhysicalProportionsRestriction.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows;
+
+namespace Microsoft.Research.DynamicDataDisplay.ViewportRestrictions
+{
+	/// <summary>
+	/// Represents a restriction in which actual visible rect's proportions depends on 
+	/// actual output rect's proportions.
+	/// </summary>
+	public sealed class PhysicalProportionsRestriction : ViewportRestriction
+	{
+		/// <summary>
+		/// Initializes a new instance of the <see cref="PhysicalProportionsRestriction"/> class.
+		/// </summary>
+		public PhysicalProportionsRestriction() { }
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="PhysicalProportionsRestriction"/> class with the given proportion ratio.
+		/// </summary>
+		/// <param name="proportionRatio">The proportion ratio.</param>
+		public PhysicalProportionsRestriction(double proportionRatio)
+		{
+			ProportionRatio = proportionRatio;
+		}
+
+		private double proportionRatio = 1.0;
+		/// <summary>
+		/// Gets or sets the proportion ratio.
+		/// Default value is 1.0.
+		/// </summary>
+		/// <value>The proportion ratio.</value>
+		public double ProportionRatio
+		{
+			get { return proportionRatio; }
+			set
+			{
+				if (proportionRatio != value)
+				{
+					proportionRatio = value;
+					RaiseChanged();
+				}
+			}
+		}
+
+		/// <summary>
+		/// Applies the restriction.
+		/// </summary>
+		/// <param name="previousDataRect">Previous data rectangle.</param>
+		/// <param name="proposedDataRect">Proposed data rectangle.</param>
+		/// <param name="viewport">The viewport, to which current restriction is being applied.</param>
+		/// <returns>New changed visible rectangle.</returns>
+		public override DataRect Apply(DataRect previousDataRect, DataRect proposedDataRect, Viewport2D viewport)
+		{
+			Rect output = viewport.Output;
+			if (output.Width == 0 || output.Height == 0)
+				return proposedDataRect;
+
+			double screenRatio = output.Width / output.Height;
+			double viewportRatio = proposedDataRect.Width / proposedDataRect.Height;
+			double ratio = screenRatio / viewportRatio;
+			double width = proportionRatio * proposedDataRect.Width * ratio;
+			double height = proposedDataRect.Height;
+
+			if (width < proposedDataRect.Width)
+			{
+				height = proposedDataRect.Height / proportionRatio / ratio;
+				width = proposedDataRect.Width;
+			}
+
+			Point center = proposedDataRect.GetCenter();
+			Rect res = RectExtensions.FromCenterSize(center, width, height);
+
+			return res;
+		}
+	}
+}